Bronze phase, TiO₂(B), and anatase nanoparticles in various weight fractions and with different sizes have been synthesized by a very facile method and their electrochemical performances have been evaluated in Li- and Na-ion cells. The transition from a layered hydrogen-titanate precursor to TiO₂(B)/anatase mixtures was monitored by in situ powder X-ray diffraction from room temperature to 800 °C. Simple NaOH treatment of the precursor inhibited the transformation of the precursor and TiO₂(B) to anatase at elevated temperatures and allowed for the preparation of larger TiO₂(B) crystallites with extra high thermal stability.